You're telling me this was the only good shot you could find on Cajon Pass with that light? Shooting around that corner in the background would have solved your sun problem. Worst case, just telemash the hell out it to minimize the straight-on light.

Who made the rules? Well it surely wasn't RP unless you are clueless about railroad photography as a whole and people like Lucius Beebe and Charles Clegg, or Jim Shaughnessy, Phil Hastings, Dick Steinheimer, Robert Hale, or Mel Patrick.

Those guys and more are the fathers of railroad photography. I would love to find Beebes "Sun at your back, Rods down, 3/4 wedge" quote as I know it's in Mixed Train Daily somewhere but don't want to read for an hour to prove a point.

The rules of good railroad photography existed long before RP came around.

As for your second question, no, it would not continue to be rejected because it is a properly lit 3/4 wedge. While not exciting, it does have a place in railroad photography, in fact it is a basic tenant of railroad photography but it must follow the rules. If it has something more, or adds some drama it is a rule that can be broken, but again your photo is not an example of any of this.